See origin errors behind WAF
Cloudflare is pwning some DDoS attacks as they come in, but the question is it says they blocked the requests due to a high number of origin errors. On my origin, I don’t see any errors at all, and Cloudflare won’t be more specific. Is there a way to see what origin errors this message is referring to?
11 Replies
Oh my, looks like they’re requesting a lot of urls that don’t exist on my server, which would be returning a 404. Would this qualify as a “high number of origin errors”
I feel like if that’s the case, there should be a different ruleset description, as currently it makes me think my server is crippling under heavy traffic
shouldn't. If you're on free, you can take a look at the error analytics page:
https://dash.cloudflare.com/?to=/:account/support/error-analytics
If that zone is Pro or higher, you can filter for origin status code
ah looks like an 520
just means their request is messed up, still shouldn’t be my server at fault right?
a 520 means your web server is returning an unknown error
Cloudflare Community
Community Tip - Fixing Error 520: Web server is returning an unknow...
Error Try the suggestions in this Community Tip to help you fix “Error 520: Web server is returning an unknown error”. Background Error 520 is essentially a catch-all response when something unexpected happens or when the origin server incorrectly interprets or does not tolerate a request due to a protocol violation or an empty response. A 52...
how many do you have? If it's less then 10 requests or so I wouldn't worry about it
yeah incorrectly or does not tolerate a request
252,000
ok I would worry about that
Error 520 is essentially a catch-all response when something unexpected happens or when the origin server incorrectly interprets or does not tolerate a request due to a protocol violation or an empty response. A 520 error occurs when the connection started on the origin web server, but that the request was not completed. The most common reason why this would occur is that either a program, cron job, or resource is taking up more resources than it should causing the server not to be able to respond to all requests properly. When this happens, you’ll see “Error 520: Web server is returning an unknown error”.possible your web server was simply being overloaded because not all traffic was being blocked? Could enable I am under attack mode if the attack is still ongoing
ahhh i think it’s actually likely it’s on server ddos mitigation
that's also a possibility
pretty sure that’s what it is, because during the attack i was about to use my server fine
but there was 100m requests across a few minutes
well i’m going to hope it’s that and leave it at that! thanks chaika 🤲